Engines and Libraries

SteveTech1

SteveTech1 is a complete multiplayer FPS engine written in Java.  It is designed be just like those "proper" engines that professionals use, like the Source engine.  It has lots of features such as client prediction, interpolation, networking, simple physics; in fact, everything you need to create a multiplayer FPS.

This video shows gameplay from Undercover Agent, the game that comes with the engine.  Almost all of my multiplayer FPS games are written with this engine.

Simple Physics for jMonkeyEngine

Features such as collision detection, gravity, forces, projectiles, bouncing etc...  Runs in the main JME thread, so is ideal for multiplayer games which need to keep in sync.

Blocky Voxel Engine

A voxel engine for Java using jMonkeyEngine.

Generic Multiplayer Connector

The Generic Multiplayer Connector is a way to easily connect any single-player game and convert it into a multiplayer competition.  This library is not designed to create an FPS, but is (for example) take something like a single-player Tetris game and get multiple instances to affect each other, e.g. when a player completes a row then speed up other player's game.